The following relates generally to wireless communication, and more specifically to beam refinement reference signal enhancement for higher mobility support.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system, or a New Radio (NR) system). A wireless multiple-access communications system may include a number of base stations or access network nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
Wireless communication systems may operate in millimeter wave (mmW) frequency ranges, e.g., 28 GHz, 40 GHz, 60 GHz, etc. Wireless communications at these frequencies may be associated with increased signal attenuation (e.g., path loss), which may be influenced by various factors, such as temperature, barometric pressure, diffraction, etc. As a result, signal processing techniques, such as beamforming, may be used to coherently combine energy and overcome the path losses at these frequencies. Due to the increased amount of path loss in mmW communication systems, transmissions from the base station and/or the UE may be beamformed.
Wireless communications between two wireless nodes, e.g., between a base station and a UE, may use beams or beamformed signals for transmission and/or reception. A beam used for such wireless communications may be referred to as an active beam, a best beam, or a serving beam. The active beam may initially be picked from a reference beam and then refined over time. For example, due to changing communication conditions, movement of a UE, etc., an active beam may be refined according to a periodic schedule and/or as needed. Thus, a UE active beam or a base station active beam may be refined. Conventional refinement techniques may include transmission of beam refinement reference signals (BRRSs) where the candidate beams are typically adjacent to the active beams. Such techniques, however, assumes that there is sufficient overlap between the candidate beams and the active beams. While this may support low mobility UEs, UEs associated with a higher mobility state may not be able to detect the candidate beam signaling and therefore drop communications with the base station.